This invention relates to a hollow building element of a plastics material comprising an upper wall, a lower wall, a pair of opposite side walls interconnecting the lateral edges of the upper and lower walls and joining members provided at the upper ends of the side walls for joining adjacent identical building elements to form a continuous structure.
Building elements of this type are disclosed in British patent specification No. 1.511.189. These building elements comprise joining members provided at both the upper and lower ends of each side wall. These prior art building elements are joined so as to form a continuous structure, such as a roof structure, by hooking the joining member provided at the upper end of the side wall of a first building element onto the joining member provided at the upper end of the side wall of a second element and by placing the joining member at the lower end of the side wall of the former building element in such a position that it is partially surrounded by the joining member at the lower end of the side wall of the second building member. Subsequently, a locking member is inserted in the space between the adjacent side walls so as to keep the pairs of joining members in intimate contact. Roof structures composed of such building elements are ordinarily anchored to a beam construction or a similar support by means of rods which are inserted into holes in the side walls and which extend perpendicular to the longitudinal axis of the building elements. These rods are inserted in annular anchoring elements which by means of screws are connected to fixing means attached to the beam structure.
The manner in which these building elements are anchored to the support necessitates that a careful calculation of the location of the fixing means has to be made before a roof structure is built in order to ensure that the above mentioned screw connections can be established when the building elements have been correctly placed on the support.